Spectroscopy and Spectral Analysis
Co-Editors-in-Chief
Song Gao
XU Xing-wei, WANG Wei, LIU Cheng, SHAN Chang-gong, SUN You-wen, HU Qi-hou, TIAN Yuan, HAN Xue-bing, and YANG Wei

Observations of the total columns of carbon monoxide(CO) in Hefei area are performed based on ground-based high resolution Fourier transform infrared spectroscopy, and we continuously collect the near-infrared solar absorption spectra and obtain time series of total column of CO through the atmosphere from September 2015 to July 2016. The observation results show that the column-averaged dry air mole fraction XCO in this area has obvious seasonal variation during the measurement period. Observation result shows that in the measured period XCO in Hefei area has obvious seasonal change. In October 2015 it has a smaller value, and then it gradually increases, in March 2016 it reaches the maximum at the end of July. Then it declines gradually, and gets to the minimum. We also analyze the reason of the XCO seasonal variation. In order to verify the observations based on the near-infrared region, we use MOPITT satellite data and CO total columns retrieved from the mid-infrared spectra collected by the same spectrometer at Hefei site to compare with the simultaneous measurements. The comparison results show that the seasonal variation of MOPITT data is similar to that of ground-based near-infrared observations, and overall MOPITT observations are higher than ground-based FTS observations. The seasonal variation and variation range of column values of CO retrieved from the mid-infrared spectra agree with those from the near-infrared spectra. The correlation coefficients between the daily averaged CO total columns of the ground-based near-infrared observations with those of satellite and mid-infrared observations are 085 and 091, respectively, which shows the high correlation and proves the accuracy of the CO total columns of the ground-based near-infrared observations. It is the first time to observe the total columns of carbon monoxide(CO) in Hefei area by using ground-based high resolution Fourier transform infrared spectroscopy, and compare them with MOPITT satellite data to get precise result. It provides the theoretical basis to understand the time and space distribution and changes of CO in atmospheric and trace source-sink distribution of CO in Hefei area.

Jan. 01, 1900
  • Vol. 38 Issue 5 1329 (2018)
  • JIN Yun-fei, JIANG Fang, and WANG Yong-mei

    In this paper, a new method for retrieving of molecular oxygen column density of the middle and upper atmosphere is presented from nadir measured data. From the cross section of absorption for oxygen molecules, we can know that the absorption of molecular oxygen in N2 Lyman-Birge-Hopfield short (LBHS) is strong but it is weak in N2 Lyman-Birge-Hopfield long (LBHL). Based on this characteristic, we propose that the nadir radiation intensity ratio of LBHS to LBHL, ln(LBHS/LBHL) can be used to retrieve molecular oxygen column density of the middle and upper atmosphere. An interpolation table for estimating the molecular oxygen column density is calculated from the airglow model. This table includes ln(LBHS/LBHL) for different oxygen contents, different solar zenith angles, satellite observation angles and solar activity conditions. Then, we get the molecular oxygen column density from ln(LBHS/LBHL) and the corresponding solar zenith angle, satellite observation angle and solar activity index. Finally, we use mode simulation to evaluate the inversion result, which proves that this new method can successfully obtain molecular oxygen column density of the middle and upper atmosphere.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1335 (2018)
  • JIZHAO Hui-zi, ZHANG Xiao-kai, QIU Jun, LU Shao-fen, XU Qing, LI Ling, and LI Xue

    Atmospheric particulate matter was collected in the hazy weather of Jinan in 2017 in order to know the status of the air pollution in the urban area in Jinan and the samples were given observation by the transmission electron microscope (TEM) and the scanning electron microscope(SEM). To better describe the morphological characteristics as to reflect the pollution characteristics of particles, we quantitatively estimated the linear dimension of the particle size (equivalent diameter)and the degree of the shape standard (shape factor), at the same time accompanied with EDS spectrum analysis to determine the microstructure of element types. It shows that on the day of smog, theshape factor of atmospheric particulate matter was smaller, as well as the the variance and standard deviation of the statistics. According to the calculation results, we could infer that morphology difference is not abvious. And most of the particles are relatively smooth, regular, nearly globose so that the surface is not easy to adsorb toxic substances or ultra fine particles. The equivalent diameter of particulate matter is larger, as well as the variance and standard deviation of the statistics. According to the calculation results, we could infer that the linear scale of particulatesare large and presented in a variety of structures, varying in size and size. Among them, blocky particles are the most, which come from the dust. Inorganic composition is mainly composed of Si, Al, Ca, Mg, Cl, K, etc. The coral reef particles come from the low temperature of the flammable substance while the spherical particles come from the high temperature. The former inorganic elements are mainly Ca, Mg and Si, while the latter are mainly Si, Al Fe. All of them come from artificial pollution. The spherical particles could be divided into three categories: smooth surface, low arched surface and rough surface, which are related to silicon, aluminum, and iron. The clubbedparticles are biological particles. And the polymeric particles come from the polymerization of fine particles, which is possible to increase the toxicity of the particles.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1340 (2018)
  • YIN Wen-yi, LIU Yu-zhu, ZHANG Qi-hang, LI Bing-sheng, and QIN Chao-chao

    Based on the density functional theory DFT/BVP86 at 6-311++g(d,p) level, the ground states of ZnO molecule under different external electric fields are optimized. The influence of external electric field ranges from 0 to 008 a.u. on the geometrical parameters, dipole moment, total energy, energy gap., Infrared spectrum and UV-VIS absorption spectrum intensity are studied. The results show that the change of molecular structure is obvious, and it becomes strongly dependent on the field strength. As the electric field changes from 0 to 008 a.u., the bond length of ZnO molecular increases. And the electric dipole moment is proved to be increasing and the total molecular energy is decreasing all the time. The energy gap of EG is found to decrease with the increasing external field. The IR vibration spectrum of ZnO molecule shows an observable red shift. The oscillator strength of UV-Vis absorption spectrum is proved to be repeating the changes of the first increasing and then decreasing. The ultraviolet absorption peak is blue-shifted with the increase of the field intensity.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1348 (2018)
  • ZHANG Jin-wei, CAO Nian, and CHEN Wu-yong

    Collagen has a unique triple helix structure, which is quite different from that of other proteins and a basis of its special effects. However, collagen triple helix structure is sensitive to environment and easy to be damaged. Recently, microwave has been used more frequently in collagen extraction and modification processes, however, there is few research of microwave irradiation on collagen structure. In this study, collagen was extracted from cattle tendon at first; then 05 mg·mL-1 collagen solution was irradiated with microwave at 30 ℃ as an experiment sample, at the same time, collagen with water bath heating and without heating as controls; finally, the Ultraviolet-Visible Spectroscopy, and Flourier Transformation Infrared Spectroscopy, Circular Dichroism and Fluorescent Spectroscopy were used to characterize the changes of collagen triple helix and supermolecular structure under microwave. It was an innovative study of the influence of microwave irradiation on collagen structure. The result showed that water bath heating and microwave could neither destroy the triple helix structure nor make collagen denaturing below the denaturizing temperature. However, microwave had a negative effect on collagen aggregation compared with water heating. In the interaction between microwave irradiation and collagen, there are both thermal effect same as traditional heating and non-thermal effect representing as negative effect on collagen aggregation. This research would provide a scientific basis of collagen structures and properties under microwave irradiation.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1353 (2018)
  • LI Xiao-nan, LIU Guo-qiang, and HU Li-li

    There are many applications which are based on the nuclear magnetic resonance with microcoils detection, such as MR imaging, spectroscopy and well logging. But due to the low Zeeman splitting difference in populations, usually the specific signal-to-noise ratio associated with the micro solenoid coils is very low. The geometry of the detection coil has numerous influences on the detected MR signals. Under a given duty ratio of the sample volume to the coil size, as well as a certain static magnetic field and so on, it is concluded that the signal-to-noise ratio is in proportion to the radio-frequency magnetic field by unit current flowing through the RF coil, and is inversely proportional to the squared root of the resistance of the coil under certain frequency. In the paper, for a 039 Tesla main field the relationship between the optimization on coil geometry parameters and the skin-depth effect of bulk conductor is addressed. Compared with sophisticated processes in MEMS technologies, the micro solenoid coils was winded with lacquered wires on polytetrafluoroethylene holding. After electronic measurement, the signal-to-noise ratio on a certain frequency for the coils made is benefit from the proper number of turns of coil. On the other hand, this fabrication is quite simplely relative to a couple of masks, lithography and electroplating. In the content of 169 MHz, i.e. the operation condition, the quality factor of a modeled micro solenoid coil is scanned in a frequency span. It is in good agreement that the simulation predicted a maximum SNR of 1998 when the number of turns is 11, under the condition of wire and coil diameter 05 and 55 mm, respectively. So the investigated principle is well verified from the practical point of view. In the future, this method can be further used in the proton density MR imaging, relaxation spectrum analysis on rock fluidics.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1358 (2018)
  • FAN Ning, SU Bo, WU Ya-xiong, ZHANG Hong-fei, ZHANG Cong, ZHANG Sheng-bo, and ZHANG Cun-lin

    The vibrational and rotational model of many biological macromolecules fall in the THz range, so THz can be used for the qualitative identification of samples. It is well known that the activity of most biomolecules can be expressed in aqueous solution. However, water, as a polar substance, has a strong absorption to THz. Therefore, many measures are adopted to reduce the impact of water for getting more information of biological samples in liquid environment. In this paper, we designed two kinds of PDMS-based sandwich microfluidic chips, which couldreduce the absorption of THz by means of micro channel. Thereforea higher THz transmission of sampleswas achieved through the terahertz time-domain spectroscopy (THz-TDS) system. The material of Zeonor 1420r wasused as substrate and cover plate, and the PDMS as channel interlayer. The transmission of the empty microfluidic chip is more than 80% in the range of 02~26 THz by THz-TDS system. Then the THz spectra of deionized water and 1,2-propanediol with different concentrations in the microfluidic chip weremeasured, respectively. The results indicatethat the THz transmission of mixtures with different volume ratios has obvious difference. The feasibility of the chip to measure liquid samples has beenproved. In addition, the solutions of potassium chloride and potassium iodide with different concentrations were detected by using the microfluidic chip, and the results show that the transmittance of THz decreases with the increase of the concentration of potassium chloride solution, while the potassium iodide solution has the reverse result. It is found that the electrolyte changes the hydrogen bond density in the aqueous solution, which leads to the change of THz absorption in solution.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1362 (2018)
  • ZHANG Xiao-xuan, CHANG Tian-ying, GUO Qi-jia, LIU Ling-yu, and CUI Hong-liang

    Spectral characteristics are obtained for Polyphenylene sulfide (PPS), Polyetherimide (PEI) and glass-fiber reinforced composites. First, by using terahertz time-domain spectroscopy system, time-domain signal of four samples are detected in free space for transmission mode. Then, according to the physical model and Fresnel formula extracting optical parameters, refractive index and extinction coefficient are calculated. Meanwhile, simulation analysis ensures the rationality and reliability of the test and calculation. Finally, based on the theory of error diffusion, error caused by crucial factors is exactly computed. Experiments show that in samples’ respective terahertz effective spectrum, PPS’s optical constants appear at n=1889~1945 (error=0003~0012), κ=0001~0047 (error=0000 1~0002 6); PPS-GF30’s optical constants appear at n=1654~1672 (error=0003~0004), κ=0001~0047 (error=0000 1~0002 8); PEI’s optical constants appear at n=1713~1733 (error=0002~0012), κ=0005~0035 (error=0000 1~0003 0); PEI-GF30’s optical constants appear at n=1688~1732 (error=0003~0004), κ=0036~0068 (error=0000 2~0002 6). The results indicate that, as a base of terahertz meta-material device, PPS is suitable for low frequency, but PEI is just the opposite. Compared with the pure samples, glass fiber reinforced PPS and PEI have been improved not only in mechanical properties but also in signal detection. In addition, detection sensitivity is stronger in the high frequency range. The study provides basic optical parameters of PPS, PEI and glass fiber reinforced materials, and it is also an important reference for meta-material device research in terahertz field.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1368 (2018)
  • MA Yun-yun, WANG Yong-qiang, MIN Qi, CAO Shi-quan, ZHANG Zheng-rong, SU Mao-gen, SUN Dui-xiong, and DONG Chen-zhong

    Ar plasma was produced by using 1 064 nm laser at atmospheric pressure, the emission spectrum was measured, and 35 Ar Ⅰ and Ar Ⅱ emission lines from the 15 upper levels were selected to make calibration for spectrometer response based on the branch ration method. In addition, the intensity response of the spectrometer was calibrated by using deuterium lamp and tungsten halogen standard light source. The calibration coefficients of intensity response for spectrometers with different gratings were obtained. The calibration coefficient of the intensity response obtained by the branch ratio method was in good agreement with that by the standard light source, and the maximum relative error is 54%. The calibration method in this paper can be used as a reference for the on-line calibration of spectral measurements in some large-scale fusion devices.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1375 (2018)
  • LI Xue-chen, WU Kai-yue, ZHANG Qi, CHU Jing-di, WANG Biao, LIU Rui, and JIA Peng-ying

    Using a micro-gap dielectric barrier discharge (DBD) decive in a parallel plate geometry, the frequency of the saw-tooth voltage has been varied to investigate the discharge image, the light emission signal and the optical emission spectrum of the DBD by using argon as the working gas. It is found that with increasing frequency of the saw-tooth wave, DBD could be in a diffuse mode less than 10 kHz, then it transits to many micro-discharge filaments occupying the whole electrode area (higher than 35 kHz) after the coexistence of micro-discharge filaments and diffuse discharge. Waveform of the applied voltage and the light emission indicates that, at a lower saw-tooth wave frequency, the diffuse discharge emits a stepped light emission signal with a high duty ratio. When increasing the saw-tooth wave frequency, the light emission transits into a multi-pulsed mode after the emergence of micro-discharge filaments. Moreover, the number of the light pulses per half voltage cycle decreases with increasing the driving frequency. The light pulse number presents one per half voltage cycle (single pulsed discharge) when the saw-tooth wave frequency is higher than 35 kHz. Scanning the optiacl spectra of the discharge, it can find the second positive system of nitrogen molecule(C3Πu→B3Πu), OH(A2Σ+→X2Π) and ArI. The spectral intensity of OH (3088 nm) and ArI (7504 nm) is investigated as a function of the saw-tooth wave frequency, and the results show that they both increase when increasing the saw-tooth wave frequency.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1380 (2018)
  • LI Ying, LI Yao-xiang, LI Wen-bin, and JIANG Li-chun

    Wood information intelligent acquiring is the key for timber quality tracing. It is also the prerequisite for timber sorting, processing and fine applications. This study aims to discuss the denoising of aspen wood near infrared spectroscopy (NIRS) with wavelet transform and develop the calibration model for wood density, to analyze the feasibility of NIR-based wood quality tracing. In this study, calibration model was developed for air-dry density of aspen wood based on NIRS and partial least squares (PLS) algorithm. Wavelet transform was used for NIR denoising treatment and model optimization. The best denoising method was determined. Aspen wood density predicted with NIR calibration model together with other wood information (species, locality of growth, measuring unit, ways of data acquisition etc. ) was recorded with QR (Quick Response) code for the quick and effective tracing. The readability and effectiveness of the QR code with varied correction levels, number of characters, and pixel sizes were compared. The results showed that: (1) The best model fitting was achieved with the decomposition layer of 5 (db5 wavelet) under the heuristic hard threshold denoising treatment. The determination coefficient (R2) was increased from 0774 8 to 0850 1 for the PLS calibration model. (2) As the number of coded characters were 217 in this study, the readability of QR code was low with pixel size of 100 px×100 px while the QR code readability was higher than 90% with pixel size greater than 100 px×100 px. The readability could be 100% with pixel size of 200 px×200 px and number of coded characters up to 600 at error correction level of 7%. It can be concluded that QR code could be an effective carrier for timber tracing information acquired with NIRS.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1384 (2018)
  • ZHAO Shuai-yang, HU Xing-bang, JING Xin, JIANG Si-jia, HE Li-qin, MA Ai-nai, and YAN Lei

    Land surface temperature (LST) plays an important role in the process of ground-air interaction and is an parameter in global change research. At the same time, the emissivity of land surface is the key input parameter of LST inversion. Mid-infrared spectrum (3~5 μm) is between visible-near infrared (038~25 μm) and thermal infrared spectrum (8~14 μm). The emissivities of terrestrial materials exhibit unique characteristics in mid-infrared spectrum, which can be used for frost monitoring and mineral composition analysis et al. Energy detected with sensor in the mid-infrared region, however, is a combination of emitted radiation from terrestrial materials and reflected radiation due to sun irradiance. The energy separation mechanism of these two parts is complicated. Therefore, there are few relevant literatures about researches on emissivities of terrestrial materials in mid-infrared spectrum. In this paper, the effective emissivities of MODIS infrared channels were calculated for a single uniform surface and a complex region with mixed pixel. It is found that the effect of surface temperature is insignificant for effective emissivity calculation in a single uniform surface. Under complex surface, the effective emissivity has a coupling effect with composition ratio of materials in the mixed pixel and surface temperatures of these materials. Within the allowable range of error, the effective emissivity of mixed pixel can ignore the effect of materials’ surface temperature. The sensitivity of emissivity error to the precision of LST inversion varies with wavelength. An accuracy of 1 K in LST retrieval requires emissivity error be constrained to within 004 in mid-infrared region, while within 002 in thermal infrared region. It can be seen that mid-infrared spectrum has much potentials in LST retrieval.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1393 (2018)
  • DENG Yu-qing, and CHEN Tao

    X-ray powder diffractometry (XRD), Infrared (IR) spectroscopy, Scanning electron microscope (SEM) and Differential thermal analysis (DTA) were used for studying the transparency in fluence factors of Shuikeng Stone from Shoushan, China. Results of IR spectroscopy and XRD indicated that the main mineral composition of Shuikeng Stone is Dickite. Order degree of Dickite can be indicated by intensity difference of wave number 3 704 and 3 621 cm-1 in IR spectroscopy and intensity difference of diffraction peaks in XRD pattern. Intensity ratio of wave number 3 704 and 3 621 cm-1 in IR spectroscopy (OI) was calculated, the result showed that OI has nothing to do with the transparency of the samples. DHI was calculated by intensity of diffraction peaks of crystallographic plane (111) and (111), the results showed that DHI also has nothing to do with transparency of samples. Results of SEM showed that the crystal particles in transparent samples show a uniform appearance and similar size and the crystallinitydegree of Dickite has nothing to do with its transparency. Results of DTA indicated that the adsorption water in transparent samples is less than that in opaque samples, and the constitution water in transparent samples is closer to the theoretical water content of kaolinite-group mineral than opaque samples. Deficiency of constitution water has caused the decline of structural integrity, accordingly, the charge balance of samples was destroyed. Adsorption water exists in crystal lattice of samples as impurity molecule because of the decrease in charge balance, these impurity molecules would decrease the transparency.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1400 (2018)
  • SUN Tong, MO Xin-xin, and LIU Mu-hua

    Visible/near infrared (Vis/NIR) spectroscopy was used to determine soluble solid content (SSC) of navel oranges with pericarp and without pericarp, and the effect of pericarp on prediction accuracy of SSC of navel oranges was investigated. In addition, Vis/NIR spectra of navel oranges with pericarp and without pericarp were acquired by a QualitySpec spectrometer in the wavelength range of 350~1 000 nm, and the effect of pericarp was analyzed from two aspects of spectrum and model performance. The average spectra of navel oranges with pericarp and without pericarp were compared, and 20 principal components that obtained were used for multivariate analysis of variance (MANOVA). Moreover, partial least squares (PLS) regression combined with different pretreatment methods was used to develop calibration models of SSC for navel oranges with pericarp and without pericarp. Furthermore, the performance of models was compared, and square of prediction residuals of samples in prediction set were used for analysis of variance (ANOVA). The results indicate that the effect of pericarp on prediction accuracy of soluble solid content in navel oranges is significant at 5% confidence level. The correlation coefficients of prediction set and root mean square errors of prediction (RMSEPs) of PLS of SSC for navel oranges with pericarp and without pericarp are 0888, 0456% and 0944, 0324%, respectively.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1406 (2018)
  • LU Shu-hua, and WANG Yin-shu

    In recent years, public security is facing serious challenges due to the frequent explosive attacks by terrorist and criminals. The analysis and detection of explosives is one of the hottest spots in the field of public security research, since explosives play a vital role in various bombs. Surface enhanced Raman scattering has been employed extensively to demonstrate fingerprint, ultra-trace and real-time detection and identification on the explosive molecules, and presents an extremely promising prospect in the field of public security including safety check and forensic science. During the last few years, the detection of explosives by SERS has become an enormously active area, resulting in significant progress. In this review, it summarizes the developments in SERS substrates including their modification and nanocomposite counterparts, the detection of organic and inorganic explosives, and the spectrum recognition of explosives. We discuss the future challenges and prospects in this field. It is believed that surface-enhanced Raman spectroscopy will be able to make greater advances in the detection and identification of explosives with the rapid development of the related disciplines such as nanoscience and technology, surface science, instrument science and machine depth learning etc.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1412 (2018)
  • ZHAO Ling-wei, CHEN Hai-long, ZHAO Hong-xia, DONG Jun-qing, and LI Qing-hui

    As a great invention in the Neolithic age, painted pottery culture changed the aesthetic way of ancient ancestors. And the famous Yangshao culture with its painted pottery’s beautiful shape, bright colors and rich ornamentation reveals the artistic features of the original and carries important social and cultural information in prehistoric times. With the accurate, nondestructive and micro damage characteristics of modern spectral analysis technology, it can provide more scientific support for the research on preservation of cultural relics. This paper makes a comprehensive analysis of the painted pottery bowls of Yangshao culture unearthed from Miao-di-gou site dated to the late Neolithic period in Shanxian county, Sanmenxia, Henan province with optical three-dimensional scanning, self-built multispectral imaging, X-ray fluorescence spectrometer (XRF) and laser Raman spectroscopy. The physical and chemical information of the painted pottery is obtained. The digital model of painted pottery bowls are constructed by three-dimensional scanning technique, and the geometric dimension of the samples is non-contacted measured and virtual restoration of digital images of samples are obtained. The similar regions of the chemical characteristics of the sample surface are distinguished from the gray image obtained by multispectral imaging. The chemical compositions and pigment phases of the painted pottery are determined by X-ray fluorescence spectrometer (XRF) and laser Raman spectroscopy. Based on the results of comprehensive research, a digital model of multi-source information of painted pottery relics is put forward, which provides basic scientific information for digital protection and display of such kind of cultural relics.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1420 (2018)
  • SHI Dong-chen, HUA Deng-xin, LEI Ning, GAO Fei, WANG Li, YAN Qing, and ZHOU Yi

    ccRaman Lidar can detect water vapor mixing ratio by atmospheric water vapor vibration Raman scattering echo signal associated with the water vapor concentration. However, vibration Raman scattering spectra would drown in the sun background light due to the weak Raman scattering echo signal, therefore the measured time is usually at night. All radiation below 300nm known at solar-blind ultraviolet band is absorbed by the ozone layer in the stratosphere. The shorter the wavelength is, the stronger the energy is. To realize the detection of atmospheric water vapor at daytime and night time, a Raman Lidar is developed at a solar-blind ultraviolet band. The system consists of the laser, telescope, photoelectric acquisition and signal processing part. Briefly, the forth harmonic output (ultraviolet 266 nm) of an externally triggered, 10 Hz repetition rate, Nd∶YAG laser is employed as the transmitter. The bore sight assembly uses a turning prism controlled by a New Focus actuator. With 400 mm diameter, 05 m rad field of view, a telescope forms the main part of the receiving optics. To obtain signals with fine separation and high efficient extraction, three dichroic mirrors separate out the detection channels by reflecting light with longer wavelengths while transmitting light with shorter wavelengths, a combination of narrow bandwidth (FWHM=1 nm) interference filters is employed to filter the backscattered signal. The rejection rate of the Mie-Rayleigh scattering signals reaches to 10-7. Before reaching the photomultiplier tube (PMT) in each channel, a plano-convex lens is employed to focus the backscattered signal on the front face of the PMT. The backscattered radiation is collected and analyzed at four wavelengths of interest, 2660 nm for the elastic scattering, 2776, 2836 and 2945 nm for the Raman scattering of O2, N2 and H2O molecules, respectively. The four PMTs output signals are then input into a multi-channel digitizer to record the backscattered signal, which is used to retrieve the water vapor profile. We use the standard atmospheric scattering models and aerosol extinction coefficients, set system of the sampling interval to 80 ns, cumulative average pulse number to 36 000, the signal-to-noise ratios of atmospheric water vapor measurement are simulated. The simulation results show that there exists influence on ozone absorbing mainly at the Solar-blind Ultraviolet Raman Lidar detection range. The signal to noise ratio simulation results show that the measurement height of the designed Solar-blind Ultraviolet Raman Lidar system can be up to 35 km during the daytime measurement. The optimal parameters of Lidar system are obtained based on the detailed analysis and the discussion of the SNR of echo signals. It is concluded that this new solar-blind ultraviolet band Raman Lidar system has the advantage of measuring the water vapor in the daytime without the influence of solar background radiation.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1430 (2018)
  • ZHANG Yan-jun, ZHANG Fang-cao, FU Xing-hu, and XU Jin-rui

    This paper presents a new hybrid optimization algorithm based on the multi-output least squares support vector machine (MLSSVM) which is optimized by quantum-behaved particle swarm optimization (QPSO). The rapid quantitative identification for the peanut oil,sesame oil, sunflower oil and soybean oil in the four - component edible blending oil can be realized with the algorithm combined with laser Raman spectroscopy. The background fluorescence was removed by baseline correction, and Savitzky-Golay filters spectral smoothing method is used for the pretreation of original Raman spectra. The quantitative analysis model based on QPSO-MLSSVM hybrid optimization algorithm is established, and the prediction set composed of 20 components is used to verify the model. The experimental result shows that it is effective for the prediction of four-component blending oil with the quantitative analysis model based on QPSO-MLSSVM hybrid optimization algorithm, and the Mean Square Error (MSE) is 0024 1, which is less than 005, the correlation coefficients of each component were above 98%. The results show that it is feasible to detect the content of each oil of four-component blending oil by laser Raman spectroscopy combined with QPSO-MLSSVM algorithm, it has strong adaptive ability and good prediction accuracy that can satisfy the multi-component mixed oil component identification.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1437 (2018)
  • MIAO Quan-long, DAI Lei, LI Bai-cheng, ZHAO Tian-qi, LIANG Kun, YANG Ru, and HAN De-jun

    This paper reports a time-correlated multi-photon counting (TCMPC) technique based on SiPM and its application to time-resolved Raman scattering measurements. Compared with conventional time-correlated single photon counting (TCSPC) technique by using photomultiplier (PMT) or single photon avalanche diode (SPAD) as photon detector, SiPM can distinguish the specific photon-number of the signal pulse, the TCMPC technique based on SiPM eliminates the limitation of the number of photons contained in signal pulse, which must be less than or equal to 1, leading to an increment of the photon counting efficiency by more than 10 times, and greatly reduces the measurement time. In addition, the instrument response function (IRF) of the time-resolved Raman scattering system is enhanced from 814 ps for single-photon to 597 ps for two-photon detection due to higher time resolution for multi-photon counting than single-photon counting measurement. As a result, it is possible to use a narrower measuring time span to suppress the fluorescence background, a kind of noise that usually occurs in conventional Raman spectroscopy. The TCMPC technique is used to measure the peak-to-background ratio of Raman spectroscopy of CCl4 with different photon numbers of 05 p.e. and 15 p.e., because the later has a higher photo-electron threshold number that can further reduce the effect of SiPM dark counting and increase the signal-to-noise ratio of Raman spectroscopy, the measured peak-to-background ratio of CCl4 459 cm-1 Raman peak has increased 64 times compared with the former. The TCMPC based on Raman scattering measurement technique is compared with the conventional one based on photomultiplier tube (PMT) and lock-in amplifier (LIA). As the timing gate of only several tens of picoseconds is utilized, effective suppression of fluorescence, ambient stray light, dark counting of SiPM and other noise effects have been demonstrated, leading to a better peak-to-background ratio for Raman spectroscopy. The peak-to-background ratios of CCl4 459 cm-1 Raman peak and Si 1st Raman peak, measured by the TCMPC based on Raman spectrometer are 39 times and 55 times as high as the values obtained by the one based on PMT and LIA, respectively.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1444 (2018)
  • CHANG Meng-fang, JIA Meng-hui, LI Lei, CHEN Jin-quan, and XU Jian-hua

    Staphylococcal nuclease is a small globular protein, whose variants are widely used in the researches on protein folding. Different from methods and techniques reported in published papers, fluorescence dynamics of tryptophan residues in two staphylococcal nuclease (SNase) variants Δ+PHS and Δ+PHS+I92A were investigated by time-correlated single photon counting (TCSPC) and femtosecond fluorescence upconversion techniques, combined with UV absorption and steady-state fluorescence spectroscopy. Based on the analysis, structures and thermal stabilities of the two SNase variants were studied. The results proved that tryptophan could be used as an endogenous probe for the structural folding and thermal stability of the SNase variants. Decay associated spectra (DAS) of SNase variants showed different changing trends upon temperatures. According to this, structural folding and thermal stability of the two variants were analyzed. Time-resolved emission spectra (TRES) demonstrated the 05 ns continuous spectral relaxation process of tryptophan residue, in which the spectral shift showed the compactness difference of folding structures of the two SNase variants. In femtosecond upconversion results, DAS of 05 ps lifetime had “positive blue edge and negative red edge”, which showed relaxation effects on tryptophan residues in SNase variants. Moreover, the lifetime of 200 ps indicated the electron transfer between tryptophan residues and surrounding quenching group. Analysis of time-resolved anisotropy showed that the tryptophan residues had independent segmental motion in the protein system, and its intensity was related to the thermal stability of SNase variants and the overall effect of thermal motion. Time-resolved fluorescence measurement and analysis of tryptophan residue helped to investigate the relationship between structure and function of protein.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1451 (2018)
  • ZHAN Yan, ZU Hong-ru, HUANG Di, and HU Chao-fan

    As a new type of fluorescent nanomaterials, graphene oxide quantum dots (GO QDs)have extensively captivated attention due to their excellent water solubility and biocompatibility. In this work, GO and hydrogen peroxide were chosen as source and oxidant, and one-pot hydrothermal approach was proposed to rapidly synthesize graphene oxide quantum dots (GO QDs) in 90 min, making a rapid, efficient and green strategy of synthesis of GO QDs. The as-prepared GO QDs showed uniform size distribution, and transmission electron microscopy (TEM) displayed that the diameter of GO QDs ranged from 225 to 525 nm. A large number of hydroxyl, carboxyl and carbonyl oxygen-containing functional groups were confirmed by Fourier transform infrared (FTIR) spectrum and X-ray photoelectron spectroscopy (XPS) analysis on the surface of GO QDs, indicating GO QDs present excellent water solubility. Photoluminescence (PL) spectra exhibited excitation-dependent photoluminescence emission of GO QDs. Based on the unique nanostructure, distinctive spectral properties and biocompatibility, GO QDs could be employed in cell imaging applications as a promising candidate of conventional fluorescent nanomaterials.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1458 (2018)
  • WU Hong-mei, GUO Yu, CAO Jian-fang, and WU Zhong-li

    A novel and simple fluorescence probe L ((E)-4-(1-(dimethylamino)naphthalene-5-sulfonamido)-N′-((2-hydroxynaphthalen-1-yl)methylene)benzohydrazide) for detection of Cr3+ was prepared by the introduction of dansyl sulfonamide fluorescent group and 2-hydroxy-1-naphthalaldehyde coordination group to p-aminobenzoic acid with chemical derivatization method. The structure of the probe L was investigated by 1H NMR, ESI-MS and FT-IR. The effect of probe L for recognition of Cr3+ was studied by fluorescence spectroscopy. The results show that the probe L shows a double peak at 473 nm (2-hydroxy-1-naphthaldehyde) and 514 nm (dansyl sulfonamide) when the excitation wavelength is 350 nm. After the addition of Cr3+ to the probe L, 2-hydroxy-1-naphthaldehyde was bonded to Cr3+, and the emission peak of dansylamine was red shifted to 540 nm (dansylamine characteristic peak). The intensity of fluorescence was increased by five times and the fluorescence quantum yield Φ was up to 028. The background fluorescence of the probe L has no effect on the recognition of Cr3+. The recognition process is presumed to be caused by the CHEF effect combined with PET (photoinduced electron transfer) mechanism. When the other metal ions were added, such as Na+, K+, Li+, Ca2+, Zn2+, Mn2+, Co2+, Cu2+, Cd2+, Hg2+, Pb2+, Ag+, the fluorescence intensity was not enhanced at 540 nm, indicating that the probe L had a high specific selectivity for Cr3+. A 1∶1 complexation stoichiometry for the binding mode of Cr3+ with L was confirmed by the model of the Job’s plot and ESI-MS result. The detection limit of L for Cr3+ was up to 40×10-6 mol·L-1.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1463 (2018)
  • WANG Xiao-ping, ZHANG Fei, YANG Sheng-tian, AYINUER·Yushanjiang, and CHEN Yun

    How to make the water quality monitoring under the influence of high levels of salt, is the key to the effective management of water quality in oases in arid areas. The author takes Ebinur lake watershed as the study area, combining three-dimensional fluorescence excitation-emission matrices (3-DEEM) with parallel factor analysis (PARAFAC), extracting three -dimensional fluorescent components of surface water in Ebinur lake watershed, constructing the index of three-dimensional fluorescence spectrum, which is fit surface water in arid area, using linear regression were establishing diagnosis model of water salt content based on the technique of three-dimensional fluorescence spectrum. The results showed that: (1) The four fluorescence components were successfully extrapolated by the parallel factor analysis modeling from the fluorescence EEM data including microbial humic-like (Component 1), terrestrial humic-like organic substances (Component 2, Component 4), and protein-like organic substances (Component 3); (2) Three-dimensional fluorescence index analysis showed that terrigenous organic pollution was the main organic pollution type in the watershed. This study indicates that the watershed is subject to human disturbance, gives the large variation of organic pollution in the water body, and the correlation between three-dimensional fluorescence index, fluorescent components and water salt content is significant; There is a significant relationship between W2, W4, W7, F355, HIX, BIX and salt water content. The correlation coefficients r in the range of 0516 and 0915, is a negative relationship between BIX and water salt content, and the correlation coefficient r is -057. (3) The application of three-dimensional fluorescence index and fluorescence component to establish salt water content produced a model fitting coefficient (r) that is greater than 07 and residual predictive deviation (RPD) that is greater than 14, the model has a high predictive ability, which demonstrated that the accuracy of the model was in line with monitoring requirements in practice. Therefore, based on the three dimensional fluorescence spectrum technology, the realization of Ebinur Lake Watershed surface water salinity diagnosis research is effective. This study not only explores the three-dimensional fluorescence characteristics of the surface water of the Ebinur Lake Watershed, but may also be applied to three-dimensional fluorescence extraction of other surface waters in arid regions of Central Asia.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1468 (2018)
  • ZHANG Ying-hua, LI Ang, XIE Pin-hua, XU Jin, HU Zhao-kun, WU Feng-cheng, QIN Min, and FANG Wu

    A new type of ultraviolet imaging method is introduced, it is useful to specific pollution gas in the pollution sources. The method is based on Lambert-Bill absorption law and reproduces the two-dimensional distribution of pollutant concentration in space with high temporal and spatial resolution by using an ultraviolet band pass filter. The measurement system is built in the laboratory to detect SO2, the measuring method about imaging technology is set forth, and the linear response and sensitivity in regard to that is analyzed. The results show that the linear response is positive and the response coefficient is as high as 0985. The sensitivity of different imaging area changes, the difference is between 1%~3%. At the same time, the accuracy of this method is discussed to get accurate SO2 column density, the result in the laboratory shows that the error about the method is around 1% and the accuracy is higher. At last, the detection limit of the method is analyzed and the space distribution of the target gas SO2 on cross section in the sample pool is parsed according to the linear least squares fitting method.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1476 (2018)
  • LI Wen-huan, ZHANG Jin-jie, YANG Cong-tai, LIU Li-na, XU Jie, LIU Xiao-huan, and FU Shen-yuan

    In this paper, the MF resin was modified by Benzoguanamine (BG). The effects of different dosage of BG on the molecular structure, tensile strength, elongation at break, resistance to combustion and boiling water resistance were respectively investigated in details. 1H-NMR spectra showed that, after the modification with benzoguanamine, the appearance of new proton signals at 70~76 ppm were attributed to the hydrogen protons of benzene ring. FTIR spectra showed that, after the modification with benzoguanamine, the appearance of 1 557 and 774 cm-1 in BG-MF resins were attributed to the skeleton vibration peak of benzene ring confirmed the success in the synthesis of BG-MF resin. X ray diffraction (XRD) analysis showed that crystal of BG-MF resin had a slight change, this was mainly due to the presence of a large amount of N elements in BG-MF, resulting in the formation of a large number of hydrogen bonds, thereby forming irregular local micro crystals. The DMA test results showed that, the peak storage modulus of MF resin was increased from 17 050 to 20 228 MPa when the BG content reaches 15%, indicating that the bonding strength of BG-MF resin was improved. The tensile strength and toughness of the dipping laminated plate were increased. The elongation at break was increased by 22% at the addition of 15% BG. The oxygen index was increased from 362 to 384, showing that the flame retardancy of BG-MF resin was improved. However, the boiling water resistance of BG-MF resin was not obvious.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1481 (2018)
  • LIU Jun-shao, HUANG Lei, XIE Wen-ju, LIN Hao, CHEN Yi-ping, and PAN Hai-bo

    Hydrophobic four phenoxyphthalocyanine zinc (ZnTPPc) was prepared on the surface of hydrophilic ZnO nanomaterialson the indium tin oxide (ITO) conductive glasswith in-situ synthesis by using DBU as liquid phase Catalyst. ZnTPPc was cyclized with phenoxy phthalonitrile as a molecular fragment and unsaturated zinc ions with dumbbellshaped ZnO(ZnO ZDs) surface as a template. The structure of ZnTPPc molecule and the characteristics of photogenerated charge in ZnTPPc/ZnO interface were confirmed by a variety of characterization methods. The photocatalytic selectivity of ZnTPPc/ZnO for the degradation of hydrophobic phenol (PL) was quantitatively analyzed by using hydrophilic methylene blue (MB), hydrophobic (PL) and their mixtures. The results show that hydrophobic ZnTPPc is synthesized by in-situ method on ZnO surface, presenting a monomolecular layer. The hydrophobic PL was preferentially adsorbed by ZnTPPc, and the relative degradation efficiency of PL is 13 times as high as that of MB under visible light irradiation.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1486 (2018)
  • MA Jie, DONG Fa-qin, HUO Ting-ting, ZHAO Yu-lian, LI Miao, LI Gang, and MENG Fan-bin

    Health effects of coexistence between atmospheric particulate matter and microbial have received more and more attention. In this paper, quartz and lead in atmospheric particles were used as the object to prepare silica dust with lead, which has different concentrations. The dust concentration was 16 g·L-1. All the work is to explore the mechanism of lead coated onto high-silica dust on cell wall/membrane injury of Escherichia coli. MTT (thiazolyl blue) was used to determine the cell viability of microbes. Compared with the control group, the cell viability of lead ion group was higher than that of the group of lead coated onto quartz dust after E. coli was treated for 2 h, it also presented a Dose effect. In PI intake test, it showed that intensity in the high concentration lead dust group was 36% and 46% higher than that in the control group, and intensity in the heavy metal group was the same as that in the former. For the Confocal laser scanning microscope, the results showed that the red fluorescence intensity of the experiment group was significantly higher than that of the control group, suggesting that the permeability of the cell membrane of the bacteria has obviously increased after treated with Pb coated onto quartz dust. The fluorescence intensity measured by fluorescence spectrophotometry showed that the intensity of ROS in the solution and cell both increased. Pb coated onto quartz dust group (Q + Pb-2, Q + Pb-3) were twice and 2.5 times higher than those in the control group, respectively. According to the previous study, the change of ROS in the solution is mainly determined by the amount of the binding state of heavy metal ions on the quartz surface. On the basis of above phenomenon, we found that Reactive Oxygen Species play an important role in inducing cell membrane damage. In the infrared characterization, the effects of Pb and Pb coated onto quartz dust on E. coli surface groups mainly attach importance to phosphodiester group, protein methylation and the amide band of the cell membrane. Those groups showed a significant peak shift after reacted with quartz dust, and all of them showed a strong combination with each other. In summary, the heavy metal and dust together changed the cell membrane permeability, destroyed the integrity of cell membrane gradually, and then affected cell viability, ultimately, the interaction lead to bacterial death. We infer that ROS, heavy metals caused damage to the cell membrane, which might be an vital toxic mechanism of Pb coated onto quartz dust.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1492 (2018)
  • PENG Jian, XU Fei-xiong, DENG Kai, and WU Jian

    It is possible to provide theoretical basis for accurate identification and quantitative extraction of water quality indicators remote sensing spectroscopy by studying the variation of water quality spectrum and its spectral characteristics under different target concentrations with Hyperspectral technology, which has been widely used in water quality testing. A total of 47 typical stations in Langya Mountain Scenic Area were selected for water quality testing and spectral synchronization in this paper. Then, seven water quality indexes and 350~950 nm bands of each test point were extracted to explore the variation of spectral characteristics of different concentration water quality indexes, and to analyze the relationship between water quality index and spectral reflectance, first derivative reflectance, any two-band reflectance ratio and difference. The results showed that the spectral curves of the water quality indexes were consistent, but their changing rules were different.What’s more, bands with the highest degree of discrimination were in the visible range. The spectral curves of water quality with different salinity, total dissolved solids and conductivity content were close to each other, and reflectivity of water samples that change the most significantly was the highest. The spectral reflectance of the water samples with higher turbidity content was more obvious, but there was no difference of spectral reflectance of different turbidity content samples in the range of 700~950 nm. The spectral reflectance of water with a dissolved oxygen concentration of 4~49 mg·L-1 was significantly lower than that of the remaining samples in the range of 350~900 nm. In the range of 350~380 nm, the spectral reflectance did not change with the chlorophyll content, and the samples with chlorophyll content close to zero were significantly lower than those of the remaining samples in the 400~950 nm bands. The spectral curves of different BGA-PC concentrations water samples were more complex than other water quality indexes in the range of 350~730 nm. In addition, the correlation between the water quality index and its original spectral reflectivity was low, but it could be improved by the combination of band reflectivity, such as the first derivative reflectance, any two-band reflectance ratio and difference. This study aims at providing a theoretical support for water quality monitoring of hyperspectral remote sensing.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1499 (2018)
  • JI Yu-shan, FANG Fang, WANG Hui-bin, MA Xiao-yan1, and LIU Ying

    The surface sediments are the source and sink of many pollutants of water. Studies have shown that phosphorus and other nutrient elements in surface sediments of Taihu Lake area, specially in Meiliang Bay and East Taihu Lake, are seriously polluted.SMT method (Standards Measurements and Testing) and molybdenum antimony anti-spectrophotometry were used to pretreat and analyze phosphorus of the 18 surface sediment samples in Taihu Lake, China, and the total phosphorus pollution was evaluated in comparison with the standards of China, Canada and the United States, respectively. Moreover, the adsorption and desorption kinetics equations were established by linear fitting, the adsorption characteristics of phosphorus under different pH and soil/water ratio were obtained. And we also studied the desorption characteristics of phosphorus under different temperature and pH conditions. The results showed that the highest contents of total phosphorus, inorganic phosphorus, organic phosphorus and acid phosphorus all appeared in S9 sampling sites, the highest content of alkali phosphorus was found in S11 sampling site. For all sampling sites, the order of average contentof each fraction phosphorus was (μg·g-1): inorganic phosphorus (40143)>acid phosphorus (37781)>organic phosphorus (17537)>alkali phosphorus (2553). The results of pollution evaluation showed that except for S12, S14~S16 and S18, other sampling sites suffered varying degrees of contamination. Both adsorption and desorption processes of phosphorus on the surface sediments followed the pseudo-second-order kinetics equation. The optimum soil/water ratio was 25∶1. The pH had different effects on adsorption and desorption, respectively. The results provided not only a theoretical basis for governing the phosphorus pollution but also credible experimental data for studying the migration of phosphorus at the sediment-water interface in Meiliang Bay and Taihu Lake.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1508 (2018)
  • DU Jian, HU Bing-liang, LIU Yong-zheng, WEI Cui-yu, ZHANG Geng, and TANG Xing-jia

    Macadamia nut is easy to spoil after being stripped off because of the high level of oil in it. Most of the existing traditional methods are destructive which are difficult to satisfy the demand of non-destructive detection. As one of the widely used deep learning models, convolutional neural network (CNN) has stronger capabilities of feature extraction and model formulation than shallow learning methods and great potential for the application of spectral data. We studied suitable CNN architecture to extract spectral features of Macadamia based on Vis-NIRS analysis, and proposed an efficient non-destructive method to identify the quality of Macadamia. At first, we took three kinds of macadamia nut with different qualities (including better nut, worse nut and moldy nut) as the research object and analyzed the spectral information in the wavelength range of 500~2 100 nm. We introduced the concept of whitening in data preprocessing to strengthen the correlation difference. In the process of model training, we divided the sample into training set and prediction set randomly and then discussed the effects of different structure parameters, such as the number of convolution layer, size of convolution kernel, pooling type, number of neuron in full connection layer and activation function. We applied ReLU and Dropout to prevent over-fitting caused by lack of data. At last, through the analysis of the classification accuracy and computational efficiency, a CNN model of 6-layer structure was established: input layer-convolution layer-pooling layer-full connection layer(including 200 neurons)-full connection layer(including 100 neurons)-output layer. The results show that the final classification accuracy of the calibration set and prediction set reached 100%. This improved CNN model can fully learn the spectral features of macadamia and classify effectively. The combination of the deep learning theory and the spectral analysis method can identify the quality of macadamia accurately, and provide a new idea for the efficient, non-destructive, real-time, online detection of macadamia and other nuts.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1514 (2018)
  • WANG Chao, WANG Jian-ming, FENG Mei-chen, XIAO Lu-jie, SUN Hui, XIE Yong-kai, and YANG Wu-de

    Accurate and non-destructive estimation on the growth status of winter wheat is of significance. The consecutive two-years experiments of nitrogen application in 2011—2012 and 2012—2013 were performed to obtain the canopy spectra and the six growth status indicators of winter wheat (Leaf area index, LAI; Above ground dry biomass, AGDB; Above ground fresh biomass, AGFB; Plant water content, PWC; Chlorophyll density, CH.D; Accumulated nitrogen content, ANC). The principle component analysis (PCA) was implemented to construct the comprehensive growth indicator (CGI), which could potentially represent the growth status of winter wheat. Furthermore, the method of partial least square (PLSR) was applied on constructing the hyperspectral prediction models of all growth indicators and validating the accuracy of CGI. The results showed that the constructed CGI significantly correlated with all the growth status indicators of winter wheat, excepting for the PWC. It indicated that the CGI could represent most of the information for the six indicators and the CGI also could be used to stand for the growth status of winter wheat. Moreover, the model performance of CGI and other six indicators were further compared, and it showed that the PLSR model of CGI performed best than other six indicators with R2=0802, RMSE=1268, RPD=2015. The CGI model was validated and proved to be more accurate and robust (R2=0672, RMSE=1732 and RPD=1489). The study showed that the CGI constructed with the PCA method could represent the growth status of winter wheat and the CGI model based on the PLSR method could be used to estimate the growth status of winter wheat. It also indicated that the multivariate statistical analysis had great potential to be applied in the field of crops by using the hyperspectral technology.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1520 (2018)
  • TANG Zhu-rui, XI Bei-dou, HE Xiao-song, TAN Wen-bing, ZHANG Hui, LI Dan, and HUANG Cai-hong

    The solid-liquid interface in which the dissolved organic matter DOM exists is the most active part of chemical reaction and microbial activity. The preseenc of oxygen-containing aromatic functional groups in DOM can affect the migration and transformation of organic pollutants and heavy metals. Compost material swine manure is rich in nitrogen elements that are beneficial to microbial growth, and its DOM structure changes may be unique. 8 representative samples of different stages of DOM were extracted from swine manure compost using UV-Vis and fluorescence spectra of modern spectroscopy, combined with the basic physical and chemical indicators of swine manure composting DOM structure and organic components of evolutionary characteristics. Thedissolvedorganic carbon and total organic carbondecreased by 5888% and 1630% respectively, which indicated that the degradation rate of dissolvedorganic carbon was higher than that ofinsoluble organic carbon. The values of SUVA254, SUVA280 and E253/E203 increased, indicating that the aromatic content of DOM increased, the content of macromolecule organic matter increased, and the number of oxygen groups increased in the aromatic ring substituents. Fluorescent volume percentage of tyrosine-like substances, tryptophan-like substances and microbial metabolites decreased from 1596%, 1814% and 2545% to 553%, 1127% and 1796% respectively, while humic acid-like and fulvide-like organic were from 1767% and 2277% to 2062% and 4462% respectively. The degradation rate of protein-like substances in the organic matter components of DOM is higher than that of humus-like substances. As the composting substances are converted into humus-like substances, the contents of protein in DOM are gradually reduced, and the content of humus-like substances andthe degree of compost stabilization are increased.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1526 (2018)
  • LI Zhe, ZHANG Fei, CHEN Li-hua, and ZHANG Hai-wei

    The chlorophyll can effectively monitoring vegetation growth status, currently the hyperspectral vegetation index (VI) is one of the common methods that have been widely applied to estimate the leaf chlorophyll content (LCC) inversion. Non-destructive rapid estimation of chlorophyll using hyperspectral remote sensing technology is a prerequisite to dynamically monitor chlorophyll content, and it is an important research issue of vegetation remote sensing. The author measured the leaf spectral reflectance and chlorophyll relative content of desert plants, analyzed the spectral curves of different desert plants under the same chlorophyll content, then transformed the SPAD value, compared Pearson and VIP methods to study the correlation between chlorophyll content and vegetation index of desert vegetation. Finally, the author selected the best fitting model from accuracy test. The results showed that: Based on the comparative analysis between Pearson and VIP, established the chlorophyll content estimation model by VIP method, selected 7 vegetation indices, which was NDVI705, ARVI, CIred edge, PRI, VARI, PSRI and NPCI respectively, the value of VIP all greater than 08, thus these 7 vegetation indices were the optimal vegetation indices. The prediction results indicated that the correlation of all models was more than 07, the best correlation between the predicted value and the measured value was the SPAD value of the reciprocal transformation, R=0816, RMSE=0007. The inversion model based on VIP method can estimate the chlorophyll content of vegetation in the study area, it provides an important theoretical basis and technical support for the practical application in the diagnosis of plant chlorophyll content.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1533 (2018)
  • ZHANG Hai-wei, ZHANG Fei, ZHANG Xian-long, LI Zhe, Abduwasit Ghulam, and SONG Jia

    Monitoring the water status of vegetation by spectral technique is one of the important means to understand the physiological status and growth trend of vegetation. In this study, the Ebinur Lake Wetland Nature Reserve is chosen as the target area. By using cluster analysis, variable importance projection (VIP) and sensitivity analysis method, the vegetation water content was classified, estimated and validated. The Results showed that in the clustering analysis method based on Euclidean distance of the vegetation moisture content is divided into three grades with higher water content, medium water content and low water content, whose ranges are around 7076%~8069%, 5327%~7076% and 31%~5327%, respectively. From 1 350 to 2 500 nm wavelength range, the spectral reflectance of water content is the lowest ,however there is no law from 380 to 1 350 nm wavelength range. By using VIP method, all vegetation water index VIP value of more than 08, indicated that vegetation water index estimation ability of water content of vegetation leaves is strong and the difference is not obvious. The MSI, or GVMI and vegetation water content cubic equation fitting is the best, the fitting coefficients of R2 were 0657 5 and 0674 2 respectively. The RWC in the range of 30%~45%, the MSI value of the NE index is the lowest. In the range of 45%~90%, the GVMI value of the NE index is the lowest. About 70% of NE value NDWI1240 index has undulation, it shows that the NDWI1240 index of the vegetation water content is at about 70% and the prediction ability is poor. Through the error analysis, the error of GVMI exponent inversion is the smallest, different vegetation indices have obvious difference in vegetation estimation results with different water contents. Therefore, it is necessary to estimate vegetation water content. In summary, using hyper spectral remote sensing technology to monitor vegetation growth and drought environment in Ebinur Lake Reserve Area is feasible.The results provide a theoretical basis for the large area inversion of satellite borne hyper spectral sensors for vegetation water content.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1540 (2018)
  • CAO Xiao-lan, CHEN Xing-ming, ZHANG Shuai, and CUI Guo-xian

    The hyperspectral data on total 927 leaves of different genotypes, which come from 4 ramie varieties, were collected under the field cultivation conditions to explore the identification and classification of ramie varieties with the hyperspectral as the basis. According to the hyperspectral reflection curve of ramie leaves, two groups of feature parameters were extracted, namely, the hyperspectral wave-valley reflectance and position parameters(the group V1) as well as the skewness and kurtosis parameters(the group V2) . Then, by adopting the stepwise discriminant approach to screen different number of variables under different F-value settings, multiple Fisher linear discriminant functions based on these two groups of feature parameters were created respectively, and further, the created discriminant functions were comparatively analyzed from the computational complexity, the accuracy and the stability. So, we can come to the following conclusions: (1) For discriminant functions under all the combinations, the overall average accuracy was 911% and the overall standard deviation mean was 12%; (2) From the comprehensive trade-off perspective, when the number of variables was between 8 and 14, the discriminant effect of the group V2 was the best among all the combinations, namely, the computational complexity was in the middle level, and both the accuracy and the stability were over their corresponding average values; among them, the discriminant functions with 13 variables had the highest average accuracy and the lowest standard deviation, which were 942% and 0% respectively; (3) When the accuracy was considered preferentially and the number of variables changed between 15 and 22, the group V1 had the highest accuracy which was 955%, however, the computational complexity under this case was higher, the stability was in the middle level and the lowest standard deviation was 09%. Above results showed that it was feasible to utilize the hyperspectral parameters together with the stepwise discriminant approach.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1547 (2018)
  • JIA Hao-yue, LI Chuang-liang, YIN Xu-mei, ZHOU Rui, QIU Xuan-bing, YANG Wen, LI Kun, WANG Gao, and WEI Ji-lin

    The concentration of titanium element in the ferroalloys was measured by laser induced breakdown spectroscopy. The maximum spectral signals were observed at the output energy of pulse laser at 50 mJ and the delay at 1 μs. Under this circumstance, traditional calibration method (TCM) and internal standard method (ISM) with Fe Ⅰ 43835 nm and Fe Ⅰ 42712 nm lines were used to quantitatively analyze the Ti in iron alloy. The fitting correlation coefficients (r) of ISM were 0997 8 and 0993 9 for Fe Ⅰ 43835 nm and Fe Ⅰ 42712 nm respectively, higher than that of TCM (0956 3). This paper presented a double-line average internal standard method and resulted in 0998 4 for r. In the range of Ti concentration from 0063% to 19%, the relative errors were 237% and 60% for the TCM and ISM respectively. However, the relative error was reduced to 39% by the double-line average internal standard method. In addition, the temperature of plasma Ti was 6 6543 K and the electron density was 1072×1022 cm-3 through calculating the obtaining lines of Ti at the laser energy of 50 mJ. Furthermore, the relationship between the laser energy and the plasma temperature was discussed in the paper.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1552 (2018)
  • CHEN Hua-zhou, XU Li-li, CAI Ken, LIU Zhen-yao, CHEN An, and LIANG Yuan-yuan

    Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was applied to rapid detection of the Trace elements (Ar, Ba, Mg, Ni) in drinking water by the three viewings of axial, radial and Synchronous Vertical Dual View (SVDV). For three different viewings, ICP-AES spectrometer is feasible to achieve rapid warm-up (only in 2 minutes). And, the acquired ICP-AES spectra performed well both for the short-term stability and long-term stability, going with a relative standard deviation (RSD) of less than 2%. The target samples were collected from three bottles of commercial drinking water and two spiked drinking water. The elements of As, Ba, Cr, Cu, Mn, Mo, Ni, V, Zn, etc were detected by ICP-AES respectively in the axial and SVDV viewings. The detection accuracy was further verified by China national standards concerning the content of trace elements in drinking water. The axial and SVDV viewings both had high detection accuracy and sensitivity. The detective results meet the standards issued by Ministry of Environmental Protection of China, and go in line with the requirements of World Health Organization (WHO). The observed content of each element did not exceed the upper limits, which indicates that the three target bottles of commercial drinking water and two spiked drinking water were available for humans.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1558 (2018)
  • FAN Hua, ZHANG Chun-yan, LI Yan-mei, YI Ling, SHEN Wei, ZAN Jin-jing, and GAO Bai

    Through three-dimensional sampling analysis, one of Jiangxi uranium ore field downstream paddy soil uranium content was measured. The results show that the uranium content in surface soil ranged from 134 to 1339 μg·g-1; using surfer software for visual mapping of uranium content in the block soil, rendering changes in figuring four groups profile of uranium content, and it showed negative correlation with the distance from the mine; uranium content was influenced by some interference, but still visible in the origin drawing software in the maximum depths of 40cm, reached more than 10μg·g-1, which may be related to plant adsorption, migration of nuclides. Through the evaluation of soil comprehensive pollution index, it can be proved that this area is in mild pollution. According to the above analysis, the leakage of waste water in the tailings reservoir of uranium mine is the main cause of these phenomena. In addition, the analysis of uranium concentration is based on the ICP-OES data, which is an important way to guide the monitoring and evaluation of the environment.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1563 (2018)
  • ZHENG Pei-chao, TANG Peng-fei, WANG Jin-mei, and LI Shi-yu

    Solution Cathode Glow Discharge-Atomic Emission Spectrometry (SCGD-AES) is a novel rapid, high efficient and real-time online element analysis method, which can be applied to metal elements detection in water. In order to achieve accurate and stable measurement of Mn elements in water, solution cathode glow discharge-atomic emission spectrometry coupled with portable spectrographs (Maya 2000 Pro) were used for the detection of manganese elements in aqueous solution in this paper, and three portable spectrographs with different entrance slit and resolution were employed for the determination. The influence of the entrance slit and resolution of the spectrograph on the spectral detection were studied experimentally, the results showed that the intensity of spectral lines increased when the entrance slit increased. The higher the resolution of the spectrograph was, the higher the ratio of spectral intensity to background intensity was was also concluded. The effects of solution flow rate and discharge current on the emission spectrum of manganese were investigated, and a higher signal background ratio was obtained at a flow rate of 186 mL·min-1 and a current of 65 mA. The spectral detection stability of manganese under optimized experimental conditions with flow rate at 186 mL·min-1 and discharge current at 65 mA was tested, and the relative standard deviations (RSDs) of the three portable spectrographs for measuring the spectral intensity of Mnin a continuous period of time were 059%, 061%, 080% respectively, showing that the stability of detection is good. The analytical performance parameters of manganese were also discussed, and the limit of detection were 428, 651, 338 μg·L-1, respectively. The manganeseelement in the calibration substance was quantitatively analyzed, andthe error range was 002%~208%, the precision ranged from 063%~154% and the recovery rate of samples was 97%~99%, which indicates that the method has high accuracy and stability. The results show that the solution cathode glow discharge-atomic emission spectrometry coupled with portable spectrographis a useful technique for accurately detecting trace manganese elements in aqueous solution.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1567 (2018)
  • ZHOU Meng-ran, HU Feng, YAN Peng-cheng, and LIU Dong

    Rapid identification of mine water inrush types in coal mine is of great significance for prevention and control. In view of the fact that traditional chemical method of water source identification is time-consuming and other problems, we put forward the fuzzy C mean clustering (FCM) algorithm and multidimensional scaling analysis (MDS) for laser induced fluorescence spectrum identification of mine water inrush and the new ideas.Because the FCM algorithm has been successfully used in spectral analysis and pattern recognition, and laser spectroscopy with fast response time, high sensitivity, less interference, the fluorescence spectra of the real-time data acquisition of water, the use of FCM and MDS on the spectral data analysis can identify sample types. A mine in east area of goaf water and Ordovician limestone water were mixed in proportion to get a total of 7 samples (each sample and 20 samples) as experimental materials, we used laser of 405nm to send laser into the measured water body, collected a total of 140 groups of fluorescence spectral data, and then selected the appropriate wavelength interval analysis. 105 sets of spectral data of each group were used as the training set, and the other 35 groups were used as the test set. We Used MDS to establish the model of five kinds of different water samples, and then used the FCM algorithm in cluster analysis to get the cluster center of the five kinds of water samples, finally useed the cluster center to test the test set. The experimental results show that there are dramatic difference between the spectra of different samples, we selected the appropriate wavelength range of spectral data, the dimension at 2 under MDS, and classfied the water samples by using FCM algorithm, finally the accuracy rate of all 140 samples reaches 100%.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1572 (2018)
  • ZHOU Xiu-qi, LI Run-hua, DONG Bo, HE Xiao-yong, and CHEN Yu-qi

    In order to improve the analytical speed of elements analysis with plasma atomic emission spectroscopy, an elements analysis system with laser-ablation spark-induced breakdown spectroscopy under high repetition rate was established and aluminum alloy was analyzed spectrally with this system. In experiment, acoustic-optical Q switched laser pulses with low pulse energies were used to ablate samples and trigger high-voltage spark discharge to enhance plasma emission and improve spectral analysis sensitivity. It was demonstrated that the peak intensity of the plasma and its time duration were enhanced and prolonged respectively under the action of high repetition rate spark discharge. The time-integrated signal intensity could be enhanced 1~2 orders and the signal was easier to be detected with time-resolved technique. The limit of detection of trace chromium reached 132 ppm while analyzing aluminum alloy with this technique. It is possible to apply high repetition rate laser-ablation spark-induced breakdown spectroscopy to elements analysis of solid samples. This technique has advantages of high scanning speed,high spatial resolution and high analysis sensitivity. It can be applied to fast scanning mapping of two-dimension or three-dimensions elements distribution of solid samples.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1577 (2018)
  • DING Kai, LI Qing-quan, ZHU Jia-song, WANG Chi-sheng, CUI Yang, GUAN Ming-lei, WANG Dan, and FAN Xing

    Airborne LiDAR bathymetry is an active bathymetry method developed in recent years, which can quickly and efficiently obtain the water depth and underwater topography, especially plays an important role in surveying on shallow water and islandreefs where ships are not accessible. In general, the maximum detectable water depth of airborne LiDAR bathymetry systemis mainly affected by the turbidity of water. Therefore, a detailed study of water turbidity of the experimental regionin advance will contribute to design the experimental scheme. In this paper, taking the coastal waters of Hainan Island in South China as an example, we studied the relationship between turbidity of water and the bathymetry performance of an airborne LiDAR bathymetry system named CZMIL (coastal zone mapping and imaging LiDAR), and presented an algorithm that can estimate the spatial distribution of maximum CZMIL detectable water depth in the coastal waters of Hainan Island by using the values of diffuse attenuation coefficient of sea water. Firstly, we studied the Kd(490) inversion algorithm in the experimental water region. Secondly, the relationship between the diffuse attenuation coefficient Kd(490) and Kd(532) was established by using the measured optical profile data in this region. Then, the relationship between the diffuse attenuation coefficient Kd(532) and the maximum CZMIL detectable depth was summarized. Finally, the spatial distribution of Kd(532) and maximum CZMIL detectable depth in the coastal waters of Hainan Island were retrieved by using MODIS data. What’s more, the distribution of maximum CZMIL detectable depth in the coastal waters of Haikou City and Lingshui City are analyzed emphatically. The results provide a reference for the LiDAR bathymetric operation in the coastal waters of Hainan Island.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1582 (2018)
  • SUN Feng, SUN Man-li, and ZHAO Xi-chen

    In consideration of the advantage of micro X-ray diffraction (micro-XRD) technology, such as micro area, trace, in situ, undamaged and so on, the author attempts to use this technology combined with the super depth of field microscopy, scanning electron microscopy, energy spectrum analysis (SEM-EDX) and micro laser raman spectroscopy(MLRM) for the first time in this paper, to observe microscopic, nondestructive analyse and identify the violet pigment sample unearthed in the site of eastern gate tower of Han Yang mausoleum. The results confirm that the composition of this violet pigment is Chinese Purple (BaCuSi2O6), accompanied by lanarkite (Pb2[SO4]O) and barite (BaSO4). Chinese Purple like type of copper barium silicate pigment was found in the ruins of western han dynasty mausoleum, which reflects that the purple colour has a high social status level at that time. And it appeared in the eastern gate tower shows that the design and decoration of western han dynasty emperor’s mausoleum in terms of the influence of theory of Five Elements. Furthermore, the discovery of lanarkite and barite makes the author to speculate that barite is Barium raw material, and lanarkite plays the part of fluxing agent and catalyst as lead additives in the process of synthesis Chinese Purple. And then it further reflects that the synthetic technology is mature enough from the perspective of the history of chemistry at that time.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1588 (2018)
  • HAN Yue-xin, JIN Jian-ping, LI Hui, LEI Da-shi, WANG Yu-bin, and GU Xiao-tian

    The carbonaceous fine-grained gold ore is one of the main types of refractory gold deposits in the world with huge reserves. The organic carbon and graphite in the ore can adsorb the cyanide complex in the solution, so the carbon-bearing gold ore needs to be pre-treated before leaching. Oxidation roasting is the best pretreatment process with the longest application time, the best reliability and the adaptability. It has been successfully used in the production practice. Traditional oxidation roasting method has the disadvantages of high production cost, complicated dust collecting system and so on. In recent years, domestic and foreign scholars have done a lot of research work on roasting process and equipment, and achieved fruitful research results, which has injected new vitality into the development of oxidation roasting technology. However, there are few researches on the theory of roasting and the research methods are relatively simple. Especially, the relevant theory of roasting process is relatively weak, which affects the development of roasting technology to a certain extent. Roasting time is the key factor that affects roasting, which determines the progress of chemical reaction and the degree of phase change. In this study, under different time conditions (roasting temperature 650 ℃), the carbon-containing fine-grained gold ores were roasted and leached. For the first time, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy spectrum analysis (EDS) and pore structure analysis were used to analyze and characterize the gold. Then the mechanism of the oxidation of carbonaceous material, the change of crystal structure and the change of phase on the gold leaching during the oxidation roasting process were also revealed. Process mineralogy study showed that the main minerals are quartz, dolomite, calcite, sericite, kaolinite, pyrite and graphite; The native gold in the ore is fine with the grain size of 5~10 μm, which is wrapped by quartz and carbonaceous debris. Carbonaceous (organic carbon and graphite carbon) has high content and fine grain size, and is closely associated with gangue minerals. The result of roasting-leaching experiment shows that the leaching rate of gold was only 1250% when the raw ore was directly leached, and the role of “carbonaceous robbery gold” was significant. With the increase of roasting time, the leaching rate of gold first increased and then changed smoothly. When the roasting time was 2 h, the leaching rate of gold was the highest. When roasting time was 1 h, the reaction of dehydroxylation was occurred on sericite, kaolinite was decomposed into montmorillonite, the pyrite was oxidized to hematite, and carbonaceous (organic carbon and graphitic carbon) was oxidized and produced CO2 but was not fully oxidized. At this moment, the d100 and d101 values and the average pore size of quartz were small, which was unfavorable to the diffusion of leaching agent, resulting in the gold leaching rate at only 5809%. When the roasting time was 15 h, the dolomite began to decompose; the carbonaceous material has completely burned. CO2 produced increased the number of micropores, which was conducive to the proliferation of leaching agent, so the gold leaching rate increased to 7334%. When roasting time was 2 h, dolomite decomposed completely, and MgO was formed. The d101 value of quartz reached the maximum (4255 03 nm), the calcareous bulk density became higher; Furthermore, the pore volume and average pore diameter reached the maximum, which were respectively 0009 954 cm3·g-1 and 6640 80 nm. The most pores produced in calcine increased the diffusion channel of leaching agent, which was beneficial to the gold leaching. The gold leaching rate also reached the maximum (9128%). When the roasting time was 3 h, the surface of sample produced Ca2SiO4, CaSO4 and so on which were easy to form low melting point material at high temperature, so weak sintering occurred. The micropores inside the particles were filled and closed, the micropores, the pore volume and the average pore size reduced. The internal structure became dense, which was not conducive to the proliferation of leaching agent, causing the decrease of the gold leaching rate.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1592 (2018)
  • HAN Guang, LIU Rong, and XU Ke-xin

    Relative measurement of near-infrared (NIR) spectroscopy is of great significance for the high precision detection of human blood glucose concentration in vivo. Although the similar background subtraction and double-beam design are frequently used in the in vitro experiments, they are not suitable for the human body detection because of the complex background variations. Reference measurement based on position is one of the most promising methods to realize in vivo reference measurement. The author proposes differential floating reference measurement method for in vivo reference measurement. The differential floating reference measurement is a universal method. However, it is difficult to determine the radial detection positions and extract the effective information from differential signals in practical use. To solve these problems, differential floating reference based on NAS (Net Analyte Signal)-VIP (Variable Importance in Projection)-SPXY (Sample set Partitioning based on joint X-Y distances)-PLS (Partial Least Square) method is proposed and the feasibility is investigated byin vitro and in vivo experiments, the results shows that the prediction accuracy and precision are improved through this method.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1599 (2018)
  • ZHANG Rui, ZHU Ji-wei, LIU Jian-li, CUI Ji-cheng, LI Xiao-tian, and Bayanheshig

    In order to meet the requirements of laser induced plasma analysis system (LIPS), the spectral resolution, spectral range and volume of the optical system. In this paper, the echelle spectrograph is developed. The spectrometer can simultaneously obtain spectral information in all spectral segments, which enables the LIPS system to perform fast, online and real-time analysis. Also, the spectrometer uses an adjustable delay time ICCD as the back end detector. The system can select the optimal delay time to receive the spectrum and improve the signal-to-noise ratio of the whole system. Finally, a set of laser induced plasma analysis system is built to verify the applicability of the echelle spectrometer in the system. By testing the alloy sample, the resolution of the whole system is 002 nm, and the spectrum range is 190~600 nm. Moreover, the LIPS system has good spectral reproducibility, and the extraction error of the characteristic element wavelength is no more than 001 nm, which can be used to analyze the composition of the sample accurately.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1605 (2018)
  • GAN Ting-ting, ZHAO Nan-jing, HU Yu-xia, YU Hui-juan, DUAN Jing-bo, LIU Jian-guo, and LIU Wen-qing

    Multi-wavelength transmission spectrum can reflect the unique information on cell size, shape, internal structure and chemical composition of a sample, so multi-wavelength transmission spectroscopy is a powerful technique for real-time and in-site detection and identification of cells. And the development of multi-wavelength transmission spectroscopy for the rapid and effective detection of bacterial microbes in water will be of great significance to the control of microbial contamination in water and the protection of the safety and health of water quality. In this paper, in order to develop the method of rapidly and accurately detecting the pathogenic bacterial microbes in water based on multi-wavelength transmission spectroscopy, the multi-wavelength transmission spectra in the range of 200~900 nm of various pathogenic bacterial microbes such as Klebsiella pneumoniae, Salmonella typhimurium, Staphylococcus aureus and Escherichia coli were obtained adopting UV-Vis spectrophotometer for the first time, respectively. And the spectral features of different bacteria and the same bacteria with different concentrations were compared and analyzed. The results demonstrate that for different bacteria, when the concentration changes, the spectral shapes in the range of 400~900 nm are consistent, and the optical density value at 400, 450, 500 and 550 nm respectively has a very good linear relationship with bacterial concentration. But in the range of 200~400 nm, the spectral shapes change with the change of bacterial concentration, and the optical density value at 200, 258, 300 and 350 nm respectively has a very good quadratic polynomial relationship with bacterial concentration. According to Mie scattering theory, Levenberg-Marquardt nonlinear least square method was adopted to calculate the scattering spectra and absorption spectra based on the measured transmission spectra of different bacteria. And the spectral features of normalized scattering spectra and absorption spectra of different bacteria were compared and analyzed. The results demonstrate that for the four types of bacteria, all the characteristic spectral peaks of scattering spectra are at 245 nm. But for different bacteria, the optical density values at characteristic peak are obviously different, which arises from the differences in cell size and shape of different bacteria. Furthermore, all the characteristic spectral peaks of absorption spectra of the four types of bacteria are at 260 nm. But for different bacteria, the spectral absorption band between 240~400 nm and spectral intensity at 260 nm are obvious different, which are attributed to the difference in content of chemical composition such as nucleic acid and protein in different bacteria. This study indicates that for the different bacteria and the same bacteria with different concentrations, the spectral features of multi-wavelength transmission spectra, calculated scattering spectra and absorption spectra are obviously different. And various parameters of bacteria can be obtained by the interpretation of multi-wavelength transmission spectra. So multi-wavelength transmission spectroscopy can be used to rapidly and effectively detect pathogenic bacterial microbes in water. This study provides an important basis for the development of rapid and on-line monitoring instrument of bacteria in water.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1610 (2018)
  • ZHANG Hao-bo, LIU Tai-ang, SHU Ru-xin, YANG Kai, YE Shun, YOU Jing-lin, and GE Jiong

    Here we proposed a new simulation model constructed by support vector machine based on near infrared spectroscopy(NIR)and electronic nose (EN) data in order to predict tobacco year. After combining the data of NIR and EN, a genetic algorithm was used to analyze and pick the relevant variants to decrease variants in the calculation. The proposed model shows a high accuracy in both the training set and the independent test set. The NIR-EN-SVM model reached the accuracy of 100% and LOOCV’s accuracy reached 9855%. The accuracy of NIR-EN-SVM model to unknown samples is 9000%.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1620 (2018)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The feasibility of 2DCOS (two-dimensional correlation spectroscopy) in the quality inspection of surimi was tested in this study.The changes of silver carp surimi protein secondary structure induced by freeze-thaw treatment were studied in suit using 2DCOS combined with ATR-MIR (attenuated total reflectance mid-infrared). The results showed that freeze-thaw cycles accelerated the oxidation process of surimi protein. The content of α-helix and intramolecular aggregated β-sheet all decreased, however the content of the anti-parallel β-sheet increased. 2DCOS analysis under the external perturbation of freeze-thaw cycles showed the change order was: α-helix, intramolecular aggregated β-sheet→antiparallel β-sheet→carbonyl. 2DCOS analysis under the perturbation of temperature showed that the protein secondary structure has been seriously damaged after three freeze-thaw cycles. And the effect of temperature on the carbonyl group of proteins was much smaller than that of the freeze-thaw cycles. These results indicated that the 2DCOS could explore and reflect the change degree of surimi protein. If these changes can be quantified, the 2DCOS could be used to detect the freshness of surimi.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1626 (2018)
  • LIU Huan, LIU Wen, HAN Dong-hai, and WANG Shi-ping

    The evaluation of milk quality is very important, which has already become a research hotspot. The non-destructive, rapid and sensitive analytical technique is urgently needed for ensuring the quality of milk. In this research, we established a new analytical technique based on three-dimensional (3-D) fluorescence spectrum, which can reflect the components information of milk with their unique fluorescence fingerprint. Compared with conventional fluorescence spectrum, the 3-D fluorescence spectrum provides more detailed and comprehensive information. By utilizing this technique, the pretreatment factors of milk are optimized by analyzing the changes of fluorescent components. Furthermore, the method can detect out 05 mg·L-1 antibiotic residual in milk. The 3-D fluorescence technique combined with Parallel Factor Analysis (PARAFAC) was used to evaluate the heat treatment of milk. A good consistency of 9763% was calculated, which indicated that the developed 3-D fluorescence fingerprint technique was credible and could be utilized as a powerful tool to examine the quality of milk.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1633 (2018)
  • MEI Yan-jun, SHAO Da, WANG Yu-hong, YANG Zhong-kang, YANG Wen-qing, GAO Yue-song, HE Shang-ming, ZHENG Yi, LI Ai-guo, and SUN Li-guang

    Two different analysis methods were applied and compared for determining high-resolution Sr/Ca ratio profiles of one modern (live-caught) and four fossil (dead-collected) Tridacna spp. samples from South China Sea. The Sr/Ca profile of Tridacna gigas in the South China Sea determined by Inductively coupled plasma optical emission spectrometry (ICP-OES) had well defined annual cycles and was significantly, negatively correlated with sea surface temperature, implying that they can be used as good proxies of historical Sea Surface Temperature (SST). ICP-OES is an commonly used method for measuring Sr/Ca ratios in Tridacna spp. shells, but it needs ex-situ, time-consuming chemical pretreatments using variable acids and considerable amounts of sample. While the synchrotron radiation X-ray fluorescence (SR-XRF) technique does not have these shortcomings, it requires little sample preparation and allows rapid in situ analysis of solid-state samples at high spatial resolution (submicron scales), and it is characterized by non-destructive, high sensitivity, and multi-elemental distribution. In this study, we tested the feasibility of determining chemical elements in shell samples of Tridacna spp. by using SR-XRF. To the best of our knowledge, no similar studies have been reported in the literature.Our study showed that the data of SR-XRF can reflect the elements contents and their ratios change. SR-XRF derived Sr/Ca ratio profiles are significantly correlated with those from ICP-OES (P-values for five Tridacna spp. samples are all <005); therefore, SR-XRF can be a promising alternative to ICP-OES. And it has a broad application potential in palaeoclimate reconstructions by using Tridacna spp.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1640 (2018)
  • WANG Shi-fang, LUO Na, and HAN Ping

    Total concentrations of As, Zn, Pb and Cr were determined in soil samples by using X-ray fluorescence spectrometry. The instrument applicability was good by analyzing the detection limit and accuracy of the instrument. Then, the energy rangesand variable numbersof heavy metal elements were obtained by using two-dimensional correlation spectroscopy. The variable numbersof Pb (10380~10740 and 12435~12900 keV), As (10380~10740 and 11610~11880 keV), Cr (5310~5520 and 5805~6015 keV) and Zn (8520~8805 and 9555~9630 keV) were 57, 44, 30 and 26, respectively. Finally, X-ray fluorescence spectrometry analysis models for heavy metal elements were established based on selected energy ranges by using partial least-squares regression. The results showed that the model performance was best for As, followed by Pb, Zn and Cr, and Rp were higher than 092. The study indicated that the prediction performance of model is improved using optimal energy ranges and the PXRF analyzer is suitable for in-situ monitoring of heavy metals in soil.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1648 (2018)
  • TIAN Quan-hui, LIU Shi-wei, ZHU Ming, and LIU Zhen

    Reasonable evaluation of spectral color reproduction and chromaticity accuracy is fundamental to evaluate the accurate of spectral reconstruction algorithm. A simple and direct evaluation index is necessary to the color reproduction. This index requires to directly characterize the spectral difference and color difference for color reproduction. Based on the study of the reproduction of the accuracy evaluation on spectral matching, this paper proposes three spectral evaluation metrics based on color visual perception. These methods are weighted spectral evaluation metrics based on human visual function. The results of weighted metrics are analyzed with Munsell color system. These metrics get the uniform distribution and stability in there replication experiment, which proves that weighted metrics are accurate metrics for color spectral reconstruction, and take into account the color perception and spectral similarity. The empirical result is that the weighted metrics indicate the actual human color perception and spectral error at same time.The metrics based on human perception solve the problem of quantitative evaluation of spectral estimation accuracy of natural spectrum matching and color spectral reconstruction.The evaluation methods in this paper show simple and intuitive color spectrum reproduction accuracy.

    Jan. 01, 1900
  • Vol. 38 Issue 5 1655 (2018)
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